1. Field of the Invention
The present invention relates generally to boat dry docking apparatus, and more particularly, but not by way of limitation, to a boat dry docking apparatus for installation in an individual boat dock which is raised and lowered by selectively introducing or exhausting air from a flotation tank attached thereto.
2. Description of the Prior Art
Many various boat dry docking apparatus have been developed and used heretofore. Recently, boat dry docking apparatus for installation in individual small boat wells or docks have been developed. Typically, such dry docking apparatus are comprised of a frame pivotally attached to the boat dock with a boat supporting cradle mounted on top of the frame. A flotation tank is attached to the lower side of the frame and air is introduced into the flotation tank to raise the frame so that the boat supporting cradle is lifted above the level of water in the boat dock, or air is exhausted from the flotation tank so that the frame and boat supporting cradle are lowered below the level of water a distance sufficient to allow the free passage of a boat to and from the boat dock.
Prior to the present invention, boat dry docking apparatus of the type described above have been relatively complex and expensive, and have been pivotally attached to the boat docks at the forward ends thereof with the rearward ends being submerged in the water or raised therein by means of the flotation tank. That is, when in the upper raised position, the frame and boat cradle of prior apparatus are positioned substantially horizontally, but when in the lowered submerged position only the rearward end of the frame and boat supporting cradle are lowered so that the boat supporting cradle is positioned at a steep angle. This makes the positioning of a boat to be dry docked and the lifting thereof difficult. In addition, due to the complexity of such boat dry docking apparatus, they generally must be shipped in an assembled condition and are difficult to install in a boat dock.
By the present invention a boat dry docking apparatus for installation in a boat dock is provided which is simple and economical, which can be shipped in a disassembled condition without the flotation tank and which can be readily assembled at the boat dock site by the owner thereof, using one or more standard cattle watering tanks as flotation tanks. In addition, the frame and boat supporting cradle of the present invention are maintained in a horizontal position both when submerged and when raised.